Prolonged hypoperfusion and early stroke after transient ischemic attack.
Many patients suffer a stroke early after a transient ischemic attack, but the reason why is often unclear. We studied 12 patients with less than 75% stenosis of the internal carotid artery and a single hemispheric transient ischemic attack lasting less than 1 hour who had a normal neurologic examination 3-13 hours later and a normal computed tomogram 24-36 hours later. Single-photon emission computed tomography using technetium-99m HM-PAO less than or equal to 50 hours after the attack showed no abnormality in eight patients, but in the other four there was an area with 30-50% reduction in perfusion ipsilateral to the transient ischemic attack. Three of these four patients developed an ipsilateral infarct 3-7 days later, but none of the eight patients with normal single-photon emission computed tomograms had a stroke during the following weeks. No difference in therapy, risk factors, severity of internal carotid artery disease, or timing of the technetium-99m study could explain these findings. We suggest that some transient ischemic attacks, though clinically identical to others, may be associated with persisting focal hypoperfusion, which predisposes to early stroke.
Bogousslavsky
J
J
Department of Neurology, Centre Hospitalier Universitaire Vaudois, Lausanne, Switzerland.
Delaloye-Bischof
A
A
Regli
F
F
Delaloye
B
B
D000368:Aged; D002560:Cerebrovascular Circulation; D002561:Cerebrovascular Disorders / Q000150:complications*; D005260:Female; D006801:Humans; D002546:Ischemic Attack, Transient / Q000150:complications* / Q000000981:diagnostic imaging / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D013997:Time Factors; D014055:Tomography, Emission-Computed; D014057:Tomography, X-Ray Computed